Steps

Question 1

En que consiste el sx de lesch nyhan

Answer 1

Exceso en la produccion de acido urico sintesis de purina de novo, ligadl a cromosoma x recesivo, como hallazgos defict cognitivo, auto mutilacion, agresion, hiperuricemia, gota distonia, macrocitosis

Question 2

Genes supresores de tumores

Answer 2

P53 produce induccion de p21, lleva a inhibicion de cdk, activacion ribosomal, y lleva a inhibicion del laso de g1 a s

Question 3

Que ocurre si hay mutacion en los genes supresores de tumorees y mencione el sx asociado por excelencia que tiene este fenomeno

Answer 3

Division dewcontrolada de las celulas como en el sx de li fraumeni

Question 4

Inductores del crecimiento tumoral

Answer 4

Factores de crecimiento como la insulina, epo, se unen al receptor de la tirosina kinasa para que pase de g1 a s

Question 5

Que tiene que ver la bomba sodio potasio atpasa con los digatilicos

Answer 5

Son inotropicos positivos porque inhiben la bimba lo que lleva a inhibir indirectamente el intercamsbio de calcio/sodio, aumentando el calcio intracelular aumentando la contractilidad cardiaca

Question 6

Que es el colagenk

Answer 6

La proteina mas abundante del cuerpo, organiza y pone recta la matriz extracelular

Question 7

Colageno tipo l

Answer 7

Es el 90%, compone el hueso, piel, tendones, dentins, fascia, cornea, y participa en la reparacion tardia de las heridas, este esta disminuido en la osteogenesis imperfecta

Question 8

Colageno tipo ll

Answer 8

Forma el cartilago, cuerpo vitreo,

Question 9

Colageno tipo lll

Answer 9

En la piel, vasos sanguineos, utero, tehido featl ,participa en la reparacion temprana de las heridas, hayndefict de este en el tipo vasculr de ehlers danlos

Question 10

Colageno tipo lv

Answer 10

Lamina basal, lentes, es defectuoso en el sx de alport, es el blanco de los anticuerpos den el sx de goodpasture

Question 11

Que es osteogenesis imperfecta

Answer 11

Enf genetica de los huesos causado por mas comunmente colia1 y colia2, la forma mas comun es autosomico dominante con disminucion de colageno tipo l, manifestaciones son: multiples fracturas y defirmidades con trauma minimo como en el parto, esclera azul, anormalidades de los dientes, perdida de la audicion por conduccion

Question 12

Defina sx de ehlers danlos

Answer 12

Produccion alterada de colageno que provoca piel hiperextendible, articulaciones hipermoviles, tendencia a sangrar. Hay varios tipos: el clasico que provoca l anterior mencionado y afecta col5a1 y col5a2, y el tipo vascular que provoca tejidos fragiles incluyendo vasos sanguinoes como la aorta, musculos, y orgsnos que se pueden reventar facilmente como un utero gravido, se da por mutacion en gen col3a1

Question 13

Como se destruye la elastina?

Answer 13

La elastasa, la cual es inhibida por la alfa 1 antitripsina,, por lo que si hay deficiencia de la alfa 1 antitripsina resulta en elastasa incontrolable rompiendo la elastina, como en el epoc

Question 14

Clinica infeccion herpes virus 1

Answer 14

HSV-1 can cause gingivostomatis (herpes labialis), keratoconjunctivitis, temporal lobe encephalitis, or meningitis. While HSV-1 typically presents “above the waist”, HSV-2 is most commonly a sexually transmitted infection that manifests with genital vesicoulcerations. The initial HSV-1 infection is typically established through the mucosal epithelium in the mouth. The virus then travels retrogradely in the trigeminal ganglion, resulting in a life-long latent infection. Subsequent stress, in turn, reactivates the virus leading to the manifestation of cold sores. Cold sores, caused by reactivation of latent HSV-1 infection, should be differentiated from aphthous stomatitis (canker sores), which have an unknown cause and do not shed viral particles.

Question 15

Cuerpos de psammoma son tipicos de

Answer 15

are cancer cells that are dystrophically calcified and have the appearance of onion skin on histology. They are also seen in papillary thyroid cancer, meningioma, and mesothelioma.

Question 16

Clinica que me puede llevar a sospechar en un cancer de ovario

Answer 16

In this postmenopausal patient with bloating, early satiety, fatigue, and ascites, ovarian cancer should be high on the differential.

Question 17

Dx de trastorno depresive persistente o distimia

Answer 17

Chronic depressive disorder or dysthymia are persistent forms of subclinical, mild depression that, by definition, last for at least 2 years with symptoms present for the majority of days and no period longer than 2 consecutive months without symptoms. Dysthymia is considered a mood disorder as opposed to a personality disorder, despite patients often claiming that they simply have a “depressed personality” to explain the long-term nature of their symptoms. To be diagnosed with dysthymia or chronic depressive disorder, the patient must NOT have any major depressive episodes in the two year period, must NOT have any episodes of hypomania which would be more consistent with cyclothymia, and retain generally normal function despite depressed mood.

Question 18

Organis retroperitoneales

Answer 18

SADPUCKER

Suprarenal (adrenal) glands; Aorta and inferior vena cava (IVC); Duodenum (except for the most proximal aspect which is intraperitoneal); Pancreas (head, neck, and body); Ureters, Colon (ascending and descending); Kidneys; Esophagus (lower 2/3); and Rectum (upper 2/3).

Question 19

48-year-old patient is recovering from acute lung injury following a diffuse pulmonary viral infection. The cell type responsible for the regeneration of the patient’s alveolar epithelium is also functions in:

Answer 19

damaged alveolar epithelial cells are regenerated by type II pneumocytes; these are the same cells that secrete surfactant. Type II pneumocytes compose about 5% of the alveolar wall, however, they are more numerous overall. Type II pneumocytes have the important function of regenerating damaged pneumocytes and secreting surfactant from their lamellar bodies.

Question 20

Caracteristicas de rechazo hiperagudo

Answer 20

In hyperacute rejection, pre-formed antibodies rapidly bind to the vasculature of the grafted tissue and result in thrombosis. Graft mottling, cyanosis, bloody urine (if the graft is already connected to the bladder), and histological evidence of vascular damage are seen.

Question 21

Mecanismo hiperagudo de rechazo

Answer 21

example of a type II hypersensitivity reaction in which immunoglobulins bind antigens on the surface of cells. This binding can mediate the recruitment of leukocytes as well as the activation of complement. This, in turn, leads to cellular damage. Other examples of type II hypersensitivity include hemolytic anemia, myasthenia gravis, and Goodpasture’s syndrome.

Question 22

Hallazgo histologico tipico de rechazo cronico

Answer 22

arteriosclerosis

Question 23

Sintomas cardinales de intoxicacion por marihuana

Answer 23

slow reflexes, paranoia, anxiety, dry mouth, and conjunctival injection.

Question 24

Mecanismo de marihuana

Answer 24

The active ingredient in marijuana (aka: weed, pot, reefer, etc.), tetrahydrocannabinol (THC), functions by binding to the CB1/CB2 cannabinoid receptor, thereby producing the effect of euphoria, disinhibition, and decrease in pain.

Question 25

Uso de marihuana en medicina

Answer 25

Aside from the use of marijuana as a recreational drug, its medicinal uses range from pain relief to glaucoma treatment to preventing nausea and vomiting in patients undergoing chemotherapy.

Question 26

Sintomas de abstinencia de marihuana

Answer 26

mild withdrawal symptoms can occur (irritability, depression, and insomnia), peak at 48 hours after last use, and last for up to 5-7 days.

Question 27

Efectos a corto y largo plazo de consumo de marihuana

Answer 27

Short-term effects can results in impaired short-term memory and motor coordination, altered judgement increasing risky sexual behavior, and in very high doses, paranoia and psychosis. Long-term effects of marijuana can interfere with normal brain development and produce symptoms of bronchitis.

Question 28

Farmacocinetica de cannabis fumada

Answer 28

Smoking cannabis only allows 50% of the THC to be inhaled with nearly 100% being absorbed by the lungs and reaches the brain via the bloodstream within a few minutes. THC distributes throughout the body depending on blood flow, and due to its lipophilicity, it accumulates in fatty tissue reaching peak concentrations within 4-5 days and slowly releases back into the blood with complete elimination taking up to 30 days.

Question 29

Microorganismos tipicos de infecciones intraabdominales

Answer 29

Bacterial infections in the abdomen are typically polymicrobial, with Bacteroides fragilis and Escherichia coli as the two most common organisms.

An abdominal infection with this organism often results from endogenous transmission from the gut due to either abdominal trauma or emergency abdominal surgery. It may be treated with metronidazole, clindamycin, or cefoxitin; however, abscesses should be surgically drained when possible.

Question 30

Wiskott-Aldrich syndrome

Answer 30

as seen by the triad of thrombocytopenic purpura (Figure B), multiple infections, and eczema (Figure A). Wiskott-Aldrich is characterized by increased IgE/IgA and decreased IgM.

Wiskott-Aldrich syndrome is an X-linked B and T cell immunodeficiency, which is caused by a defect in the WASP gene on the X chromosome. It causes T cells to be unable to reorganize their actin cytoskeleton and leads to the clinical triad mentioned above. Increased IgE/IgA, decreased IgM, and normal IgG are observed on serologic evaluation. Treatment consists of an HLA-matched bone marrow transplant.

Question 31

Criterios de laboratorio para dx siadh

Answer 31

low plasma sodium (< 135 mEq/L ), low plasma osmolality (< 275 mOsm/kg, )inappropriately concentrated urine, increased urinary sodium, urine osmolality > 100 mOsm/kg, and urine Na > 40 mEq/L , and normal body fluid status (euvolemia). 10-15% of small cell lung cancers present with SIADH; however, other causes of SIADH beyond paraneoplastic include CNS disturbances such as infection, stroke, hydrocephalus, or trauma as well as a medication side-effect from NSAIDs, antidepressants, chemotherapy agents, clofibrate, carbamazepine, and narcotics.

Question 32

Local side-effects of topical corticosteroids

Answer 32

skin atrophy, telangiectasia, hypertrichosis, acneiform eruptions and striae.

Question 33

Que es flutamida

Answer 33

non-steroidal antiandrogen that acts as a competitive inhibitor at testosterone receptors. It is used in combination with a GnRH analog, such as leuprolide, in the treatment of advanced prostate cancer. It is given in a continuous manner as to act as an antagonist

The inhibitory effect of flutamide on the tumor’s testosterone receptors is beneficial to halt the progression of prostate cancer. However, there is also an unwanted increase in systemic testosterone levels seen with flutamide monotherapy due to reduced negative feedback at the level of the pituitary. The addition of a leuprolide counters this unwanted increase in testosterone levels by decreasing the release of LH and FSH from the anterior pituitary, thereby reducing androgen production. Note that upon administration of leuprolide, there is an initial surge n LH and FSH before achieving suppression. Combination flutamide/leuprolide therapy has side effects associated with reduced androgen levels, including hot flashes, gynecomastia, and impotence.

Question 34

Que es y como se caracteriza la urticaria

Answer 34

a dermatologic disorder characterized by pruritic wheals that form after mast cell degradation. Wheals are often described as pale red, raised, pruritic bumps and can occur anywhere on the surface of the skin. Most cases of urticaria are short in duration and are caused by an allergic reaction. Urticaria is distinct from contact dermatitis, which is a type IV hypersensitivity reaction that occurs only at the site of contact with an allergen.

Question 35

Primera linea para tratar urticaria

Answer 35

non-sedating, second-generation antihistamine (histamine H1 blockers), which can be titrated to higher than standard doses.

Question 36

Maneo de urticara cronica que no remite a primera linea

Answer 36

omalizumab therapy, disease remitted within weeks in 86% of patients, with half achieving complete remission. They conclude that omalizumab is an effective and safe treatment for refractory chronic spontaneous urticaria with rapid onset of action for inducing and maintaining remission.

Question 37

Que es y me anismo de fenoldopam

Answer 37

Fenoldopam is used as an antihypertensive agent by acting at D1 receptors, which activates adenylyl cyclase, elevating the levels of cAMP and therefore producing vasodilation of the renal arterial beds. This results in an increase in renal perfusion, leading to increased diuresis and natriuresis. The drug promotes sodium excretion via dopamine receptors in the nephron. Fenoldopam has a rapid onset of less than ten minutes, a very short half life of 5 minutes, and must be given IV. Other dopamine agonists include: dopamine itself (which has selectivity for both D1 and D2 receptors as well as A1 and B1) and bromocriptine (which is a selective D2 agonist that is used primarily for the treatment of Parkinson’s disease and prolactinemia).

Question 38

Clinica de deficiencia de vitamina e

Answer 38

6-month-old boy presents with decreased growth, pigmented retinopathy, hemolytic anemia, and peripheral neuropathy

Question 39

Causa de deficiencia de vitamina e

Answer 39

Deficiency of this fat-soluble vitamin is rare, but can be caused by diseases that cause fat malabsorption such as cystic fibrosis (CF) and abetalipoproteinemia.

The typical patient has impaired absorption of the fat-soluble vitamins (A, D, E, and K); conditions that may cause this include pancreatic insufficiency, Crohn and celiac diseases, cystic fibrosis, cirrhosis, cholestatic liver disease, and small bowel bacterial overgrowth. Abetalipoproteinemia is a rare recessive genetic disorder caused by a mutation in the microsomal transfer protein (MTP) gene. This loss-of-function mutation in MTP prevents assembly of apoB in the liver and intestine, leading to the absence of circulating apoB-containing lipoproteins such as LDL and VLDL and impaired transport of fat-soluble vitamins.

Question 40

Cariotipo de mola hidatiforme

Answer 40

69 XXX or 69 XXY

Question 41

Como se diferencian las molas parciales de las completas

Answer 41

Partial moles can be differentiated from complete hydatidiform moles in that complete moles lack any fetal tissue and exhibit diffuse trophoblastic proliferation. Complete moles are also associated with higher levels of Beta-hCG as well as an increased risk of malignant trophoblastic disease (ex. choriocarcinoma) in comparison to partial moles. Additionally, unlike partial moles, complete moles are associated with a 46 XX or 46 XY karyotype, with both sets of chromosomes of paternal origin.

Question 42

Clinica tipica de taponamiento cardicacp

Answer 42

evidenced by the findings of an enlarged cardiac silhouette and pulsus paradoxus. Immediate evacuation of the pericardial sac is essential to prevent hemodynamic collapse.

Pulsus paradoxus is an exaggeration of the normal variation in systolic blood pressure with inspiration, defined as a decrease in systolic blood pressure of >10mm of Hg during inspiration. The “paradox” is that one can detect beats on cardiac auscultation during inspiration that cannot be palpated at the radial pulse. These physical exam findings are found in cardiac tamponade due to the pressure placed on the heart by the fluid filled pericardial cavity. Beck’s triad (jugular venous distension, distant heart sounds, hypotension) are exam findings that are consistent with the diagnosis of cardiac tamponade.

Question 43

Como se podria imtoxicar con etilenglicol

Answer 43

Por consumo de un liquido antocongelante

Question 44

Como se produce la intoxicacion por etilenglicol

Answer 44

Ethylene glycol is a colorless, ordorless, sweet-tasting liquid Note, antifreeze, which is mainly composed of ethylene glycol, can be a number of colors. The toxicity of ethylene glycol is derived from the product of its hepatic oxidation - oxalic acid. Ethylene glycol is first degraded by alcohol dehydrogenase to glycoaldehyde then by aldehyde dehydrogenase to glycolic acid then finally to oxalic acid, the toxic metabolite. Oxalic acid binds to calcium and forms calcium oxalate crystals that damage the heart, brain, lungs and kidneys. Fomepizole is a competitive inhibitor of the first enzymatic step in this process, preventing the conversion of ethylene glycol into its toxic metabolites.

Question 45

Como se trata imtoxicacion con etilenglicol

Answer 45

Fomepizol

Question 46

Cariotipo de sx klinefetlers

Answer 46

47: XXY

Question 47

Que es el sx de kliemerfelter

Answer 47

results from nondisjunction during meiosis or due to a translocation; one of the extra X chromosomes becomes a Barr body. Klinefelter’s affects as many as 1 in 500 to 1,000 males and is a typical reason for infertility in men, and the rate is estimated to be even higher in those who are mentally retarded (1 in 100). The syndrome leads to the dysgenesis of seminiferous tubules and loss of Sertoli cells. As a result there is a cascade of effects, including a decrease of inhibin resulting in an increase of FSH. This increase of FSH upregulates aromatase leading to the increased conversion of androgens to estrogens. Similarly, there is Leydig cell dysfunction which leads to a decreased production of testosterone and a resulting increase in LH.

Question 48

De que celulas derivan los melanocitos

Answer 48

De las de la cresta neural

Question 49

Que celulas ademas de los melanocitos vienen de las celulas de la cresta neural

Answer 49

melanocytes, neural crest cells give rise to: autonomic nervous system, dorsal root/autonomic/cranial ganglia, cranial nerves, celiac ganglion, adrenal medulla chromaffin cells, enterochromaffin cells, parafolicular cells of the thyroid, Schwann cells, pia mater, arachnoid mater, skull bones, odontoblasts, laryngeal cartilage, and the aorticopulmonary septum.

Question 50

Como encontraria los examenes en el caso de sospecha de un adenoma de la pituitaria que me cause cushing

Answer 50

In the setting of high baseline ACTH, suppression of cortisol with a high dose of dexamethasone indicates pituitary adenoma as the cause of disease.

Question 51

Causas de cushing

Answer 51

The most common cause of Cushing syndrome is the administration of exogenous steroids (iatrogenic Cushing). Several endogenous processes can also produce Cushing syndrome, including pituitary adenoma (Cushing disease, 70% of endogenous cases), adrenal adenoma (15% of case), and ectopic ACTH production (15% of cases). To distinguish between a pituitary adenoma that produces ACTH and an ectopic carcinoma producing ACTH, a dexamethasone suppression test is completed.

Question 52

Histologia que me lleve a pensar en carcinoma de celulas escamosas em esofago

Answer 52

Biopsy of the esophagus reveals dysplastic cells, but does not show evidence of glands or increased mucin,

Question 53

Epidemiologia y etiologia del carcinoma de celulas escamosas

Answer 53

Worldwide, SCC is the most common esophageal cancer and it is especially common in developing countries. It is believed that the mechanism leading to SCC development involves mutations in several genes responsible for tumor suppression (e.g., p53). SCC masses present small early in the course of disease but can eventually grow large enough to fill part of the esophageal lumen and cause obstruction (another common patient presentation). Evidence of glands or increased mucin on biopsy would suggest adenocarcinoma, which is not linked to smoking.

Question 54

Factores de riesgo para carcinoma de celulas escamosas de esofago

Answer 54

along with smoking and alcohol consumption, ingestion of lye, diets lacking vegetables, esophageal webs, and achalasia

Question 55

Virus predominante en causa de esofsgitis en inmunocomprometidos

Answer 55

Hsv 1

Question 56

Por que se da fisiopatologicamemte el sx de hungtintom

Answer 56

loss of neurons in the caudate nucleus and putamen.

Question 57

Que cromosoma se afecta en el sx huntintom

Answer 57

autosomal dominant disorder caused by CAG triplet repeat expansion in the Huntingtin gene (found on chromosome 4

Question 58

Caracteristicas de una agammaglobulinemia ligada al cromosoma x

Answer 58

In this disease, the Bruton tyrosin kinase (Btk, on X-chromosome) gene is mutated, resulting in impairment of the pre-B cell receptor and an arrest in pre-B cell maturation. The result is the absence of mature B-cells and agammaglobulinemia. Symptoms such as those described in the question typically appear around 6 months when most/all maternal immunoglobulins have been degraded. An absence of CD19+ cells confirms diagnosis; CD19 is a component of the B-cell co-receptor (CD19, CD21, and CD81). When the co-receptor and B-cell receptor (composed of an Ig and CD79) cluster during antigen binding, CD19 is phosphorylated intracellularly and initiates a cascade that helps lead to B-cell activation (along with BCR signals).

Question 59

Que papel juega la hidroxiurea en la anemia de celulas falciformes

Answer 59

Patients with sickle cell anemia are often treated with hydroxyurea. This has the effect of increasing the HgbF in circulation.

Hydroxyurea increases the amount of HgbF in circulation while raising the amount of total hemoglobin in the body. The result is that HgbS has less of a chance of pairing with each other and resulting in a sickled red blood cell leading to a sickle cell crisis. Hydroxyurea is often used to reduce the length and number of sickle cell crises in patients with severe disease. It should be noted that hydroxyurea has no role in the management of an acute sickle cell crisis episode, but is often continued during acute crises given its role in chronic management.

Question 60

Que me puede provocar la deficiencia de vitamina b1 o tiamina

Answer 60

Thiamine, or vitamin B1, deficiency is most frequently seen in alcoholics and malnourished patients. Thiamine deficiency may lead to Wernicke-Korsakoff syndrome and beriberi. Wernicke’s encephalopathy is characterized by a triad of confusion, ophthalmoplegia and nystagmus, and ataxia. Korsakoff’s psychosis is characterized by memory loss, confabulation, and learning deficits. Symptoms of dry beriberi includes polyneuritis and symmetrical muscle wasting, usually of the lower extremities. Wet beriberi is characterized by high-output cardiac failure due to dilated cardiomyopathy.